Effects of Rubus occidentalis extract on blood pressure in patients with prehypertension: Randomized, double-blinded, placebo-controlled clinical trial

Nutrition. 2016 Apr;32(4):461-7. doi: 10.1016/j.nut.2015.10.014. Epub 2015 Nov 6.


Objective: Black raspberry (Rubus occidentalis) is known for improving vascular function. However, there has been no study evaluating its effects on 24-h systolic and diastolic blood pressure in prehypertensive patients. The aim of this study was to examine those effects.

Methods: Patients with prehypertension (N = 45) were prospectively randomized into a moderate-dose black raspberry group (n = 15, 1500 mg/d), a high-dose black raspberry group (n = 15, 2500 mg/d), or a placebo group (n = 15) during an 8-wk follow-up period. Raspberries were consumed in the form of a dried powder extract that was fashioned into capsules. The capsules contained 187.5 and 312.5 mg of raspberry powder, which was equivalent to 1500 and 2500 mg raspberries. Ambulatory 24-h blood pressure (BP); central BP; pulse-wave velocity; abdominal visceral fat; serum renin; angiotensin-converting enzyme; and inflammatory cytokines such as interleukin-6, tumor necrosis factor-α, C-reactive protein, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and plasminogen activator inhibitor-1 were measured at baseline and at 8-wk follow-up.

Results: High-dose black raspberry significantly reduced 24-h systolic blood pressure (SBP; 3.3 ± 10 mm Hg versus -6.7 ± 11.8 mm Hg; P < 0.05) and nighttime SBP (5.4 ± 10.6 mm Hg versus -4.5 ± 11.3 mm Hg; P < 0.05) compared with controls during the 8-wk follow-up. Black raspberry powder did not produce any significant changes in most of the parameters other than BP.

Conclusion: The use of black raspberry significantly lowered 24-h BP in prehypertensive patients during the 8-wk follow-up. Black raspberry used as a dietary supplement could be beneficial in reducing SBP in prehypertensive patients.

Keywords: 24-h blood pressure; Arterial stiffness; Black raspberry; Central blood pressure; Prehypertension.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Blood Pressure / drug effects*
  • C-Reactive Protein / metabolism
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Intercellular Adhesion Molecule-1 / blood
  • Interleukin-6 / blood
  • Intra-Abdominal Fat / metabolism
  • Male
  • Middle Aged
  • Peptidyl-Dipeptidase A / blood
  • Plant Extracts / pharmacology*
  • Plasminogen Activator Inhibitor 1 / blood
  • Prehypertension / drug therapy*
  • Prospective Studies
  • Pulse Wave Analysis
  • Renin / blood
  • Republic of Korea
  • Rubus / chemistry*
  • Tumor Necrosis Factor-alpha / blood
  • Vascular Cell Adhesion Molecule-1 / blood


  • ICAM1 protein, human
  • IL6 protein, human
  • Interleukin-6
  • Plant Extracts
  • Plasminogen Activator Inhibitor 1
  • SERPINE1 protein, human
  • Tumor Necrosis Factor-alpha
  • Vascular Cell Adhesion Molecule-1
  • Intercellular Adhesion Molecule-1
  • C-Reactive Protein
  • ACE protein, human
  • Peptidyl-Dipeptidase A
  • Renin